Earth Science News  





. Lungless frog could shed light on evolution: scientist

The Barbourula kalimantanensis. Photo courtesy David Bickford.
by Staff Writers
Jakarta (AFP) April 11, 2008
The discovery of a rare species of Indonesian frog that breathes without lungs could shed light on how evolution works, a scientist said Friday.

Dissection of the frog, which was found on Borneo last August, showed it breathed entirely through its skin, biologist David Bickford told AFP.

While many frogs breathe partially through their skin, the Barbourula kalimantanensis is the first to have entirely evolved away from having lungs, he said.

This runs counter to one of the key events in evolution, when animals developed primitive lungs and moved from water to land.

"Here is a frog that has reversed that trend, it has totally turned against the conventional wisdom, if you will, of millions of years of evolution," said Bickford, a biologist at the National University of Singapore.

The frog appears to have shed its lungs over millions of years to adapt to its home in the fast-flowing cold water rivers in the island's rainforests, Bickford said.

Cold water contains more oxygen, making it possible to breathe through skin, he added.

Only three other amphibians -- two species of salamander and a worm-like creature called a caecilian -- are known to have evolved to breath without lungs.

"It's like a cookie, it's almost completely flat. So initially when you pick it up in the water you know this thing is strange," said Bickford.

"It's surprisingly cute, you know, like a bulldog is cute. It's one of those things that is so ugly, it's cute."

While many animals have organs they no longer use -- such as the human appendix -- evolution normally works on the principle of "if it's not broke don't fix it," Bickford said.

"Most things we don't use don't get lost... so there had to be a big negative side-effect of having lungs for them to be lost."

Bickford believes lungs may have made the frog's ancestors too buoyant in the fast-flowing water, increasing their risk of being swept away.

The downside, Bickford said, is that the frog cannot survive on land or even in still water.

Indonesian scientist Djoko Iskandar, who accompanied Bickford on the expedition, first heard about the strange-looking creature 30 years ago and had been searching for it ever since.

He said that every time he went to Borneo he found habitats had been destroyed by industry, with pollution to rivers from gold mining apparently making it impossible for the frogs to breathe.

"We think that a little bit of pollution will affect the skin, and the skin is more important than for other species," said Iskandar, a scientist at the Bandung Institute of Technology in Indonesia, adding that even a small amount of pollution could be devastating.

Hundreds of new species of insect, animal and plant have been discovered on Borneo, with a find every month on average, conservation group WWF has said.

Other recent exotic discoveries include poisonous "sticky frogs," "forest walking catfish" able to travel short distances out of water and the transparent "glass catfish".

Community
Email This Article
Comment On This Article

Related Links
Darwin Today At TerraDaily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
When Genetics And Geology Meet In Patagonia
Halifax, Canada (SPX) Apr 10, 2008
When Charles Darwin first set foot on Patagonia, he was a fresh-faced 22-year old yet to finesse his revolutionary theory of evolution by natural selection. But traveling around the tip of South America aboard the HMS Beagle-part of an epic, five-year scientific expedition-the young naturalist had his eyes opened to the immense diversity of species and landscapes.

.
Get Our Free Newsletters Via Email
  



  • Big Tokyo quake would cause human gridlock: study
  • Disasters In Small Communities: Researchers Discuss How To Help
  • Raytheon Develops Advanced Concrete Breaking Technology For Urban Search And Rescue
  • Floods, cyclones, devastate southern Africa: UN

  • Market alone can't halt CO2 emissions: British climate official
  • Ethiopia seeks nearly 70 million dollars to deal with drought: UN
  • Absence Of Clouds Caused Pre-Human Supergreenhouse Periods
  • Low-Carbon Living Takes Off In The US

  • General Dynamics AIS Completes Testing For GeoEye's Next-Gen Earth Imaging Satellite
  • Harris Ground System For GOES-R Weather Satellite On Display
  • Project Explores Using NASA Earth Science Data For Enhanced Utility Load Forecasting
  • India to launch remote sensing satellite this month

  • Analysis: India eyes Kazakh energy
  • Oil, environment, lifestyle fuel Asia's two-wheeler boom
  • Commentary: Iraq oil circus came to town
  • ConocoPhillips, NREL and Iowa State To Establish Biofuels Research Alliance

  • China rejects human-to-human bird flu report
  • Human infects human with bird flu in China: study
  • Alligator Blood And Mud Help Fight Superbugs
  • Bird flu breaks out at Tibet poultry farm: China

  • Researchers Develop New Conservation Map For Biodiversity Hotspot
  • Lungless frog could shed light on evolution: scientist
  • And The First Animal On Earth Was A ...
  • Grand Canyon May Be As Old As Dinosaurs

  • Ships dumping waste in Mediterranean illegal as of 2009: UN
  • Russian mayor urges closure of own town: report
  • Czech steel giant promises to improve air quality in polluted city
  • Harmful Algae Taking Advantage Of Global Warming

  • Plan Brokered By UCLA, USC Archaeologists Would Remove Roadblock To Mideast Peace
  • Scientists Find A Fingerprint Of Evolution Across The Human Genome
  • The Voyage To America
  • Dyslexia in Chinese, English speakers is different: study

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement